Wind Wheel Under Grille - Extended Range Innovation -

Wind Wheel Under Grille - Extended Range Innovation -

So I was looking online at electric cars and their range and then I started to think about the wind resistance cars get on the road and how that could translate to creating electricity. I got to thinking on the model S they could place a long narrow water wheel shaped wind turbine across the bottom front end bumper so that as air passes through from wind resistance it charges the battery as it moves along to create a self sustaining system by adding to the current range of the car. The Germans have started testing using wind charging as a stop and go technique in Australia but I got to thinking that it would make more sense if Tesla made an aerodynamic wind wheel located under the front grille. There are light weight materials you could make it out of so it would not slow the car and cause drag such as carbon fiber or aluminium e.c.t.

Just thought I would provide this idea to Tesla I am in college now and am getting to be a bit creative when looking at ways to improve things. Hope someone has a look at this idea and feel free to ask any questions !

Volker.Berlin | 17 novembre 2011
Brian H | 17 novembre 2011

The slowing and dragging has little to do with the weight of the materials. Friction and thermodynamic inefficiencies and conversion losses mean you never recover the energy put into "pushing" the fan ("wind wheel") through the air. And all that energy came from the very same battery you're trying to fill.

I have a deal for you! A crisp new $100 bill for only 6 old wrinkled $20s. I can supply as many as you want.

VolkerP | 17 novembre 2011

Nice thought experiment for any college attendant:

A volume of air sits still. Kinetic energy is zero.
A car passes though that volume, making air swirl. Kinetic energy is transferred from the car to the air.

There is no way to gain back more energy from the air than used to move the car, since the energy content is zero at the start.

Volker.Berlin | 17 novembre 2011

Enter Model S version 6.0 with a sub-zero Cd (just a few years from now...), passing through the same volume of air. Now you have a thought experiment! :-)

EdG | 17 novembre 2011

This is another example of how the Model S would get better range in stop and go traffic than on the highway. On windy days, when stopped, you extend a wind/electric generator. Before you go, retract it. What could be more fun!

jbunn | 17 novembre 2011

Innovator93, when you get to your Physics classes you'll note devices of this type violate the first and/or second laws of thermodynamics.

Simply, you expend energy to drive the car forward to generate the "wind". You collect the wind energy imperfectly since your fan and generator suffer from friction and losses in the generator. You then put this back into the battery suffering losses in the charging process. You take energy out of the battery to drive the car forwarward with the motor suffering friction losses, inefficiencies in the motor, etc... This generates less wind, etc, etc... Keep repeating the cycle. Energy leakes away to heat with every iteration. Entropy must be maximized.

Just one cycle probably has a total efficience of less that 40%

Kind of sad, but not only can't you generate power, you can't even break even. Entropy must be maximized.

Stationary wind generation does not violate thermodynamics because the energy comes from the environment. Even that is subject to thermodynamics. Ultimatly the entire process is driven by nuclear processes and friction from gravitational attracction but that's still maximizing entropy.

EdG | 17 novembre 2011

Do you want to change "Entropy must be maximized" to "Entropy must increase"?

Hopefully we, as life itself does, can find ways in which entropy is increased minimally.

stephen.kamichik | 17 novembre 2011

I believe that airplanes are equipped with wind turbines. In the event of a catastrophic failure, the wind turbine is deployed beneath the fuselage. The turbine then generates electricity to run the essentials of the airplane.

Mycroft | 17 novembre 2011

Yeah, if they were smart, they would deploy wind generators on jets. Since the jets are flying so much faster, just imagine how much electricity they could generate!

jbunn | 17 novembre 2011

EdG. I could go with Entropy must increace.

Stephen, if so, any power gained is offset by a larger net loss of kinetic and potential energy. Drag from the turbine would slow the airplane (kinetic), resulting in an eventual decreace in altitude (potential) I say this only to help our young student not get his hopes up.

I believe commercial aircraft have APU's (Aux power units) that are turbine driven generators running off aviation fuel from the aircraft main tanks.

jbunn | 17 novembre 2011


Electrical energy generation on aircraft from turbines would be enough to supply major power to the grid, but is offset by the aerodynamic drag of the tied together extension cords hanging off the tail of the plane.

But I think I just figured out why the turbine wheels give the car extra range.

AndyM | 17 novembre 2011

Even if we could break the thermodynamics laws, no fan is going to provide the 0.3 kWh/mile required to keep the the batteries topped up. Do the math.

kuarak | 17 novembre 2011

Inovator93 keep that idea on mind. You can't achieve a perpetual motion machine(laws of thermo and all those things), but I imagine you have a point if you see the idea with the same concept as the regenerative brakes. (A way to recharge partially the batteries)

The fan could generate a current, and they'll have to study if it's efficient or not. Maybe the weight of the fan could increase the consumption of power more than the fan can generate, or maybe not in which case will be a good innovation.

Brian H | 18 novembre 2011

Weight is irrelevant. If the fan is attached to the car, the push of the wind is also a push on the car. Then you start wasting energy getting the spin-generated % of that push into the battery.

Guaranteed loser.

jbunn | 18 novembre 2011


The energy density of wind is rather low. If you really want to get usefull power, you get it from the drive train. A luxury sedan at speed has a lot of kinetic energy you can recover when you decelerate.

Tesla deliberatly chose not to use hub motors for a couple reasons. Total weight particularly unsprung weight, difficulty with making hub motors for alternating current, cost of having 4 motors, etc. It would have given all wheel drive, and all 4 wheels would regen.

In the Tesla, only the back wheels can regen. Braking on the front is friction only. I'm guessing the Tesla will attempt to regen on light braking, but eventualy the front calipers come into play then it's lost to heat.

Driving in reverse however.... Now that will charge the car. (kidding)

Zelaza | 18 novembre 2011

Time to stop this nonsense of a wind turbine refilling he battery. The arrangement is another example of an impossible perpetual motion machine of the simplest kind and will not provide more energy to the battery than is extracted from the battery to accommodate the additional load of the turbine. For every Watt generated by the wind turbine the motor has to put out more than that Watt to move the arrangement through the "wind". Further, even more power than that has to come out of the battery to drive the motor.

If you still believe in the possibility of this wind turbine arrangement working, then you would be much better off, and not require any additional equipment, by simple stepping on the brakes while driving with your foot on the pedal and using the regenerative braking to supply the battery. This, of course, is ridiculous, but not more so than the perpetual motion machine arrangement. Time to learn some basic physics.

EdG | 18 novembre 2011

I believe Tesla has decided, for simplicity of design and, therefore, reliability, to do regen only when removing your foot from the accelerator. Braking is simple braking.

The level of regen you get when lifting your foot may be programmable.

Brian H | 18 novembre 2011

Zelaza, back off and bug off. For the umpteenth time, Innovator brought up a perpetual motion/free energy scheme. They've all instantly been shot down. This thread is actually a rehash of many others.

Your self-importance is seriously undeserved.

Brian H | 18 novembre 2011

There's an xkcd for every situation. I think a year or two ago I started at the beginning and read them all. My fave may be the one with our hero facing a dude standing in mid-air, who says, "The universe does NOT work the way you think it does." Or WTTE.


hey. | 12 juin 2013

Just read over this and confused. Who cares if the wind turbine wouldn't charge the car back to full battery? If you were able to install a light wind turbine into the grill of a car, or spirals along the side inside of vents, wouldn't it be able to partially re charge the battery and extend the number of miles that you can drive on a single charge?

txjak | 12 juin 2013

@hey: Yes and No.

Yes: If the car is parked on a hill facing into the wind, the wind could recharge the battery, just like any other windmill.

No: If the car is moving and there is no wind, then the turbine adds drag and the amount of energy generated would be less than the energy used by the car to create the relative wind due to the extra drag. Net loss of range.

Theoretically, a windmill that was oriented perpendicular to the direction of travel and was enclosed in a fairing that minimized forward drag could generate some energy from winds that crossed the path of travel. This would be what I call the sailboat effect. I doubt it would produce enough energy to make it worth doing, however. Think about only running the car using the prevailing winds, like a sailboat, and how much "sail" you would need to make it useful. :-)

Wayne3 | 12 juin 2013
Tim.Enfinger | 5 octobre 2014

It is NOT against the rules of physics to suggest a wind turbine could be used to increase the range of an electric vehicle by providing some regenerative effect to the batteries. Why? Because the car is MOVING ANYWAY. If someone were to argue they were going to build a propelled vehicle to push a wind turbine down the road to generate a wind field which would then be used to turn a turbine to create electricity, of course they would never get more energy out than they put in. But, a car, by necessity, has to move anyway and the wind field is a by-product of that movement. It is about re-capture.
The principle is the same as capturing the energy from an exhaust gas stream in an internal combustion engine (i.e., a turbocharger). Do turbochargers require more energy than they (help) create? Absolutely not. All else being equal, a turbocharged engine is more efficient than a non-turbocharged engine.
Suppose a couple of canned type wind turbines were strategically placed to minimize drag, maybe where air flowed anyway - like in a brake cooling duct, the issue is not about perpetual motion. the real question is could the necessary components be made light enough to warrant the extra regeneration they provided? I think if the car were constantly moving, the answer is absolutely yes (we are talking about extending range, not running perpetually). The problem is the extra weight may not be worth it considering stop and go type driving.

Dwdnjck@ca | 5 octobre 2014

So.. If we take a funnel and connect it to the hose of a dyson vacuum cleaner....

johncrab | 5 octobre 2014

It takes energy to produce energy. A wind turbine on a car may produce electricity but it will always consume more in terms of drag resistance than it can generate.

PBEndo | 5 octobre 2014


The windmill on the car can only produce energy that it gets from the car pushing it through the air. This requires the car to use more energy to push the windmill than it it were not there. The energy that the windmill can capture and return to the battery will be less than the amount the car had to use to push it.
The only way the windmill idea would actually result in a net energy gain is if the car is parked in a windy area allowing some small amount of recharging to occur from the wind's power, or while traveling downhill. In the first case, the weather is supplying the energy to spin the windmill. In the second case, gravity is. When you are driving on flat terrain, or uphill, the Tesla battery is supplying that energy.

The Turbocharger uses energy that is created by the ICE but is normally wasted. The pressure of the exhaust gets captured and is used to force more air into the combustion chamber. This is a completely different situation.
You reference perpetual motion a few times so I assume you have been told that a perpetual motion machine is impossible already.
For people that don't have a great understanding of physics, it is often helpful to take thought experiments like this to the extremes to get an idea of why they don't work.

Consider this. If your idea was capable of supplying some free energy with 2 small ducted fans, than why wouldn't 2 more provide a little more energy? Take that to the extreme and you will see that for every fan added (according to your argument) you will get some additional return of energy. If you keep adding ducted fans at some point the amount of energy created would exceed the amount required by the car to move forward through the wind. At that point, you could disconnect and drop the battery since the little windmills are supplying more power than it needs to keep moving. This would reduce weight and the car would really take off! Then you would have a car that runs by itself, with no internal source of power, right?

Suppose a couple of canned type wind turbines were strategically placed to minimize drag
Take this to the extreme. A windmill requires drag - that is what makes it turn. If you minimize drag to the extreme, the windmill will not turn at all!

Tim.Enfinger | 5 octobre 2014

Ok. I am struggling with this. If we connect a funnel to a Dyson, that Dyson had a turbine-generator, and that turbine generator were connected to a battery, then the Dyson could be made more efficient (nowhere near self-sustaining), right? It would certainly be more complicated and more expensive.

Why doesn't a turbocharger create more back-pressure and thereby consume more energy than it produces? Drag applies to a turbocharger, correct? My reasoning is because the exhaust stream exists anyway, then a turbocharger captures energy that would just otherwise be lost. Another way of looking at this is if a group of tiny, short-lived, but incredibly productive creatures lived on the roof of a Tesla, and decided to build a wind turbine to generate electricity from the wind they noticed was passing by, the electricity they produced would be net positive to them. Their wind turbine on the roof would be equivalent to them to our wind mills on earth - just capturing energy that happens to be there anyway. In theory, they could supply said electricity to the battery, thereby increasing the car's range. Thanks for the fun thought experiments, and patience.
I think I may be wrong, but it is still fun to think about.

Tim.Enfinger | 5 octobre 2014

Thanks PBEndo. I posted before I saw your reply. This was fun. Thanks for humoring me.

Tim.Enfinger | 5 octobre 2014

Yep, I admit I am wrong. BUT, if we put an ICE in the Tesla and then captured its exhaust to turn a turbine to make electricity... Just Kidding! Thanks again. I'm outta here...

AndyO | 5 octobre 2014


Tim.Enfinger | 5 octobre 2014

AndyO - I love it! Do you have a patent? LOL | 5 octobre 2014

TANSTAAFL: An Acronym that should be memorized by every inventor who is attempting to develop a perpetual motion machine.

AndyO | 5 octobre 2014

It's from a book my parents read to me about 60 years ago. I remembered enough to do a Google image search and found it - The Penguin that Hated the Cold. That image stuck with me. | 5 octobre 2014

T = There
A = Aint
N = No
S = Such
T = Thing
A = As
A = A
F = Free
L = Lunch

Taught to me by a Physics Professor on the first day of class.

PBEndo | 5 octobre 2014
Brian H | 5 octobre 2014

Inspiring. A perpetual motion proposer who actually gets it when it is explained! I'm impressed.

Mark K | 5 octobre 2014

Nicely done PBendo, and a very reasonable response from Tim.

Windmills assert drag upon wind to harvest energy.

Drag is EV enemy number one at freeway cruise. You want less of that, not more.

One other axiom - never convert energy if you could just use it in its present form. Conversion is lossy.

That helps people who think regen can compete with conservation of momentum.

Only for the special case of sufficiently higher drag at very high speed, does regen storage have any merit vs. just keeping your momentum.

Hence coasting down hills is generally more effective than regen.

lvaneveld | 5 octobre 2014

@ Tim, I did not see an clear answer on part of your post so I thought I would clear that up. A turbocharger does not really create more energy or power than it uses in an internal combustion engine. What you have to be careful about is where you think about the limits of your envelope when you look at power and energy.

Yes hit is true that a turbocharged engine produces more power than the same engine without turbo. However it is not the turbocharger that produces that energy. The turbo captures waste energy from the exhaust stream to compress air fuel mixture going in. However all the additional power coming from the engine is actually produced from the fuel, not from the turbo.

The turbine is probably about 80% efficient and captures a small amount of energy that is used to force more fuel into the engine. The compressor is also probably about 80% efficient making an overall efficiency of about 60% to 70%. Possibly less, not likely better. It is the increased amount of fuel forced into the engine that is the source of the increased horsepower.

bonaire | 5 octobre 2014

Great way to save energy on your trips is to choose to go shorter distances or even not go at all. Maybe park and just tilt at windmills?

Tim.Enfinger | 6 octobre 2014

@Ivaneveld. I'm really enjoying this. I know just enough to "be dangerous". Your post got me to thinking about my assertion that, all else being equal, a turbocharged ICE is more efficient than a non-turbocharged engine. Maybe that is not true? How can forcing more air into the engine, thereby also requiring more fuel, be "more efficient"? On second thought, isn't the real benefit of a turbo that it can, when active, produce more power from a smaller engine? In other words, the fuel savings come into play for the time (majority of time?) when the turbo is not active - you can get away with a smaller engine. The turbo is only needed for higher load demands (like accelerating quickly). Let's assume that we have two 2.0 liter ICEs that are exactly the same mechanically, but one has a turbo (thus has greater hp on tap). There is no reason the turbo engine would be more fuel efficient, is there? I promise to stop talking about ICEs on a Tesla forum now.

logicalthinker | 6 octobre 2014

Reading the perpetual motion machine suggestions here makes me embarrassed to be a member of the human race.

It's a similar feeling I get to when people stand up at meetings with Elon Musk and announce that they want him to hire them because they are super geniuses and want to change the world, etc.

#CRINGE #AWKWARD #iWanttoCrawlintoaCave&Hide

Tim.Enfinger | 6 octobre 2014

@logicalthinker. I understand your frustration. I did not think I was proposing a perpetual motion machine (in hindsight, I regret my original post was so assertive, as opposed to inquisitive). I know enough to understand perpetual motion is impossible. I just did not understand the physics/mechanics nearly well enough. I was thinking since the wind field is already there anyway relative to a moving vehicle, why not use it? I thought the answer might have been because the added weight and complexity made it not worthwhile. I was a solid C student in math and science, but have an open mind. Take heart that at least one person has learned something in the last couple of days.

PBEndo | 6 octobre 2014

There seem to be 2 general categories of perpetual motion machine questions. One group doesn't understand or has never heard of the concepts that refute perpetual motion at all.
There is another group, that has a incomplete concept of it and they get fooled by scale. They often say things like "Of course, the magnets would not produce enough energy to make it a perpetual motion machine, but it could extend range".
What they fail to realize is if a generator on the front wheels, or the wind turbine, or magnets on the transmission were able to capture even a tiny amount more energy than it takes to make them work, and therefore extend the range, that is still a perpetual motion machine. Just a very small one. The size or the amount of energy is irrelevant. You can't get something for nothing. This is where taking it to the extreme seems to help some understand.

Oh wait, I left out the group that thinks it is all a conspiracy.

rmitchum | 6 octobre 2014

There are three kinds of people in this world.
Those that CAN count, and those that CAN'T. :-)

Brian H | 6 octobre 2014

No, 10 kinds. Those who understand binary, and those who don't.

Rocky_H | 6 octobre 2014

@Tim, I'll maybe expound a little on the "wind passing by" concept. Yes, it is, but that's why the field of aerodynamics and coefficient of drag is so huge. They desperately want that air to slip around the car, rather than pressing against its surfaces. If you let it slip by, it's exerting less force against the front of the car. However, if you have that press against fan/turbine blades to make them spin, that means it is exerting force against those surfaces. And since those surfaces are attached to the car, that means they are also pressing against the car, slowing it down (or needing more energy to keep up the speed).

As Brian H mentioned, I'm also glad that you are learning from this.

jjs | 6 octobre 2014

Am I the only one that thinks the entire exchange is outstanding? I think this is a shining example of the best of what we can hope for.
- Question/Assertion
- Explanation
- Humility and understanding
- Growth
- Humor

Tim.Enfinger I tip my hat to you.

@rmitchum and @Brian H - Made me smile. Thanks.

renwo S alset | 6 octobre 2014

But what about hanging a magnet in front of it?

Dwdnjck@ca | 6 octobre 2014

It would have to be a three phase magnet.